A discussion about the Obamacare deadline extension quickly devolved into a shouting match Wednesday on MSNBC's "All In With Chris Hayes," as a guest representing Americans For Prosperity accused Hayes of lobbing personal attacks against her.

Hayes introduced Jennifer Stefano, the Pennsylvania state director for AFP, as someone who he thinks "genuinely wakes up every day and thinks about how to destroy Obamacare."

Any pretense of civility disappeared from the segment soon after that, when Stefano was set off by Hayes pointing out that she denounced the deadline extension as harmful to families and Medicaid recipients while offering no solution herself for insuring those families.

Hayes also pushed back against Stefano's claim that the uninsured were not signing up for coverage, pointing out that Medicaid expansion did most of the work covering individuals who were not previously insured. When Stefano claimed that families pulling in $94,000 per year were included in the Medicaid expansion, Hayes shook his head and called that a "math trainwreck" -- in 2014, a family of 4 that earns roughly $31,721 is considered to be at 133 percent of the poverty level.

"You know nothing about me," Stefano said. "You have no idea why I wake up in the morning … you know nothing about my family. You don't know if I was born and raised in a trailer park."

“How dare you, like Harry Reid, try to undercut the voice of a woman simply because she disagrees with you," she continued. "Now you may not like where I’m coming from on policy, but you have no right to undercut my voice!”